1. Field of the Invention
The present invention relates to a processing apparatus of an insulative substrate for use in a PDP (plasma display) manufacturing apparatus, a master writer manufacturing apparatus for a DVD (digital video (or versatile) disc), a substrate processing apparatus for a hard disc manufacturing apparatus, a reticle fixing apparatus in an EB (electron beam) exposure apparatus, and a CVD, etching or sputtering apparatus for manufacturing elements to be formed on SOS (silicon on sapphire) and SOI (silicon on insulator) wafers.
2. Description of Prior Art
In the manufacturing apparatuses for such as a DVD, a PDP or the like, a material to be processed is a glass substrate which shows electrically insulative characteristic. Therefore, in the conventional art, since it is impossible to electrostatically attract these substrates within a vacuum, they are flatly placed on a stage in the manufacturing apparatus thereof or they are fixed with a mechanical mechanism.
A reticle of the EB exposure apparatus is comprised of quartz which also shows electrically insulative characteristics. Therefore, conventionally, the reticle is fixed under a vacuum with a mechanical mechanism.
SOS wafers and SOI wafers, attracting attention as next-generation alternatives to silicon wafers, show electrically insulative characteristic with regards to the surface by which they are mounted on a stage. Therefore, conventionally, it is impossible to apply a fixing method using an electrostatic chuck in the manufacturing apparatus for forming devices on these wafers. A means and a principle of electrostatically attracting a silicon wafer are disclosed, for example, in Japanese Patent Application Laid-Open No. Hei 5-63062 (1993), however it is impossible to electrostatically attract an insulative substrate in accordance with the principle.
Also, there is known an apparatus for electrostatically attracting a paper, for example, an electrostatic plotter.
As the level and integration is advanced in the process for forming devices or the like on a substrate for use in a DVD, PDP, or a hard disc, or on an SOS or SOI, the temperature control in the process comes to be very important. With regards to the conventional process for forming devices on a silicon wafer, the temperature control is conducted in the process using an electrostatic chuck.
However, since the electrostatic chuck of the conventional art can attract only a conductor or semiconductor, a material to be processed cannot be electrostatically attracted in a case of having an electrically insulative characteristic. Therefore, it is impossible to control the temperature in the process with high accuracy.
Therefore, an electrostatic chuck, with which an insulative substrate can be electrostatically attracted, and a processing apparatus using such an electrostatic chuck are desired.
For fixing a reticle in the EB exposure apparatus, there is also desired a method using an electrostatic chuck, the structure of which is simpler than that of a mechanical fixation and which has less of a problem of generating dust particles.
According to the present invention, for solving the problems mentioned above, there is provided an electrostatic chuck which can electrostatically attract an insulative substrate, such as a glass substrate, under a vacuum atmosphere and a heating/cooling apparatus and a temperature controller apparatus for an insulative substrate using such an electrostatic chuck.
In the electrostatic chuck according to the present invention, the distance between a plurality of electrodes which are provided on one side of a dielectric constructing the electrostatic chuck is made small, and the thickness of the dielectric is made thin. A potential difference is given between the electrodes so as to form a non-uniform electric field upon an attracting surface of the dielectric. An insulative material to be processed being within the non-uniform electric field is partially polarized, and generates gradient force that is attracted in the direction being strong in the strength of the electric field. The gradient force is expressed by Fxe2x88x9dxcex1xc2x7grad E2, wherein F is gradient force, xcex1 an inductive polarization charge, and E an electric field. The present invention utilizes this effect.
For obtaining the effect mentioned above, according to one aspect of the present invention, there is provided an electrostatic chuck for attracting an insulative substrate, used under a vacuum atmosphere by specifying the shape and the properties of a dielectric, and the shapes of electrodes.
According to another aspect of the present invention, there is provided a heating/cooling apparatus, comprising the electrostatic chuck mentioned above, a plate in which a flow passage is formed to supply or diffuse heat generated in the process or heat to be supplied to an insulative substrate by a medium, and a gas supply conduit for supplying a gas which is enclosed within a space defined between the insulative substrate and the attracting surface of a dielectric for adjusting heat transmission therebetween, wherein the pressure of the enclosed gas can be used to adjust the temperature of the insulative substrate and thereby the temperature can be adjusted to a predetermined value.
According to a further aspect of the present invention, there is provided a processing method for an insulative substrate under a vacuum atmosphere, using the electrostatic chuck mentioned above.
According to still another aspect of the present invention, there is provided an apparatus for electrostatically attracting an insulative substrate under a vacuum atmosphere, using the electrostatic chuck mentioned above.